Materials handling apparatus



Jan. 2, 1962 c. vv BERGSTROM 3,015,401

MATERIALS HANDLING APPARATUS Filed on. 30, 1958 3 Sheets-Sheet 1 INVENTOR. CARL M 85965 TROM L ATTOR V EYZ;

Jan. 2, 1962 c. v. BERGSTROM 3,

MATERIALS HANDLING APPARATUS Filed Oct. 30, 1958 v 3 Sheets-Sheet 2 Fig. 3

f INVENTOR. CARL v. BERGSTROM C. V. BERGSTROM MATERIALS HANDLING APPARATUS Jan. 2, 1962 3 Sheets-Sheet 3 Filed Oct. 50, 1958 Fig. 8

Fig. 7

INVENTOR. CARL I/ BE R65 TROM United States atent 3,015,401 MATERIALS HANDLING APPARATUS Carl V. Bergstrom, 645 E. Ocean Blvd, Long Beach, Calif. Filed Oct. 30, 1958, Ser. No. 779,897

5 Claims. (Si. 214-317) (Granted under Title 35, (1.5. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to material-handling apparatus and, in particular, to apparatus for hoisting, transporting and dumping both hinged-bottom and skip box type containers.

As is well known, there are several different types of material-transporting containers, although most such containers in ordinary commercial and industrial use have several features in common. Thus, these containers customarily employ lug members projecting laterally outwardly from each side, these members being adapted to be engaged by the forks of forklift trucks, if such trucks are being utilized, or by the conventional chains of other mobile handling apparatus such as the Dempster- Dumpster trucks. In addition, many conventional containers have a bail portion which usually constitutes a bent steel rod welded along the upper edge of one of the container sides; this bail being engaged by a hook customarily carried by the hoist of the mobile material handling unit.

As to the different types of containers, these roughly divide into two categories one of which includes those containers which have an open top and solid bottom and which are dumped either by tilting to pour the material from the open top or by manually removing the material from the container. These containers generally are known as skip-boxes. Another category includes those cou tainers known as the hinged-bottom type and this type generally is characterized by the fact that the material is unloaded by opening the bottom and permitting the material to pour through much in the manner of a hopper. The apparatus of the invention is adapted for use with either of these types. The structure of both types will become more apparent in the subsequent description.

There have been a number of difficulties experienced in the use of both the skip-box and the hinged-bottom types of containers. For example, Dempster-Dumpster trucks have limited utility in that they are designed primarily for one type or another but not both. Also, when it is desired to use such a truck to dump a hingedbottom container into a receptacle disposed at a relatively high level, the trucks cannot raise the container to the desired height. On the other hand, forklift trucks are capable of raising containers to appropriate elevations, but their usefulness is limited by the fact that they are not designed to handle hinged-bottom containers. Further, the present fork-lift trucks of the type adapted to engage the laterally-projecting lugs of the containers have their forks fixed at a particulm lateral spacing so that they can handle only containers of a particular size.

It is therefore an object of the present invention to provide a simple, relatively-inexpensive fork-lift type of materials handling mechanism which is capable of hoisting and dumping hinged-bottom containers.

A further object is to provide apparatus according to the last object which is capable of handling not only hinged-bottom containers, but also open-top containers, such as skip-boxes.

An object related to the last object is to provide such an apparatus which is capable of handling different sized containers.

3,015,401 Patented Jan. 2, 1962 ice object is to provide laterally-expandable fork lifts adapted to engage the laterally-projecting lugs of both the hingedbottom and open-top type of containers, and, correlative to this object, to provide specially-formed forks that can engage the lugs in any laterally-adjusted position.

A further object is to provide an attachment for a conventional fork-lift truck, such an attachment fulfilling the objects noted above.

'Other objects will become apparent in the ensuing description and claims.

The objects of the present generally are achieved by providing a preferably mobile unit with .a pair of hoist mechanisms. As contemplated in the preferred form one of these mechanisms will be the conventional hoist mechanism'of a fork-lift truck, while the other is a frame member that is carried by but vertically reciprocable independently of and relatively to the conventional hoist of the truck. This frame member carries a hook adapted to engage the aforementioned bail of the particular container, while the conventional or main hoist of the forklift truck carries the laterally-spaced forks.

However, in the present invention, these forks are adapted to-engage the aforementioned laterally-projecting lugs of either an open-top, skip-box type of container or a hinged-bottom type. The result is that a container can be engaged both by the forks and by the hook of the reciprocable frame; the conventional hoist of the truck then being driven to raise or elevate the container to a desired point. At this point, the main hoist is held stationary and the reciprocable frame of the attached hoist then driven to open the bottom ofthe hinged-type container and permit the dumping of its contents. The bottom of the container swings open in response to the vertical movement of the frame because this vertical movement elevates the hinge of the bottom and causes the bottom to pivot on the laterally projecting lugs of the container. The dumping of the skip-box type of container is accomplished entirely by the main or conventional hoist of the truck, although various features of the present invention cooperate in its handling.

Another particularly important feature of the invention employed in the preferred form is the fact that the laterally-spaced forks are adjustable to permit the handling of different sized containers. As has been noted,

these forks are adapted to engage the conventional lateral-' ly-projecting lugs of the special containers under consideration, so that such width adjustment becomes quite important. Most suitably, the forks are pivotally carried by the framework of the conventional or main hoist of the truck and special means, such as hydraulic drive mechanism is used to swing the forks outwardly when a container of greater width is to be handled. Also, the laterally-projecting lug-engaging portions of the forks are specially formed and, most suitably, these portions have a particular arrangement for engaging the logs of a hinged-bottom container and another arrangement for engaging the lugs of the skip-box type of container. These fork arrangements are of such a nature that proper engagement can be effected in any laterally-adjusted position of the forks. However, these details, as well as others which are of significance in the present invention can be better understood in the subsequent description with reference to the drawings.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a perspective elevation of a fork truck emthe main mast removed;

I as. shown on the drawings,

3 FIG. 2 is a front elevation of the auxiliary mast structure showing the operating means thereof;

FIG. 3 is a fragmentary top view of FIG. 2;

' FIG. 4 is a sectional view taken along lines 4-4 of FIG. 3;

FIG. 5 is a side elevation of the top portion of the trucks main mast indicating the operation of emptying a bottom dump container;

FIG. 6 is a similar view indicating the operation of emptying a skip box;

P16. 7 is a front elevation of the and FIG. 8 is a side elevation of the hydraulic system.

This invention is capable of being incorporated on existing fork lift trucks of any standard. type such as ilhydraulic system;

lustrated in FIG. .1 however it is understood that the deand 6 is pivotally mounted on bracket '84 which is suitably secured to transverse member 18. A pair of coupling links 81 and 82, are secured to the releasable latchtail of'the truck proper constitutes no part-of the present invention, therefore a detailed description is deemed un- 7 necessary. 7

The truck as shown in FIG. 1 is indicated generally by the reference numeral 10 having a conventional vertical.

mast, with a portion removed, indicated generally by the numeral .11 comprising a pair of outer upright members 12 and 13, inwhich are slideably mounted a pair of channel members 14 and 15. A lift carriage 16 is secured to the slideable members 14 and 15 in any convene tional way. Vertical movement-of the inner slideable' channel members 14 and 15, together with lift carriage 16, is effected by means of power actuated means controlled by the operator.

A pair of L shaped horizontally spaced load supporting forks 21 and 22 are pivotally secured in any suitable way to the upper transverse member 17 of the lift carriage 16 at 23'and 24 respectively. Secured to' the forward extended portion 25 and 26 of the load supporting 7 forks are the load supporting attachments 27 and 28 respectively. As seen, for example, in FIGS. 1 and 2 of the drawing, load supporting attachment 27 consists of '34 which are secured, at their anchor ends 35 and 36 by anchor brackets 37 and 38 to plates 39 and 40 respectively. Plates 39 and 40 are suitably secured, as by welding, to the lower transverse member 18. The plungers '41 and 42 of the hydraulic cylinders 33 and 34 are secured. to brackets 43 and 44 which are suitably mounted on the inside surfaces 48 and 49 of the lift forks 21 and 22 respectively. The hydraulic feed line 50 as shown in FIGS. 7 and 8' from hydraulic source and control, not shown, is positioned over a pulley 51 secured to existing structure on truck 10 in any suitable manner and connected to the hydraulic cylinders 114 and 115 by a series of connections, a swivel 54, T 55, flexible hose 56, and a pair of Us 57 and 58 to hydraulic cylinder 114. Another L 59 from T connects to hydraulic cylinder 115 Another feed line 60 from hydraulic source and control, not shown, is positioned over pulley 61 and is connected to the hydraulic cylinders 33 and 34 by a similar arrangement having connections 64, 65, 66 and 67. j

A pair of return springs 70 and 71 as shown in FIG. 2 are suitably secured to the surfaces 48 and 49 of. the lift forks 21 and 22 and plates 39 and 40 respectively. A pair of stop pins 74 and 75 are secured to transverse member 18 which prevents the lift forks from pivoting inwardly beyond a certain point. Another pair of stop pins 76 and 77 located further out on member 18 restricts the lift forks from pivoting outwardly beyond a certain point. A releasable latching arm 79 for maintaining a skip box in the horizontal position as shown in FIGS. 4

ing arm 79 and extended shaft 84, which runs parallel and above transverse member 18, as shown in FIG. 2, respectively. A latch control arm 83 is mounted on the outside end of extended shaft 84, as shown in FIG. 1, 6 and 5 enabling the latch control arm'freedom of movement. The control arm 83 is connected by a line 85 to an automatic reel 86 located on the truck 10 convenient to the driver. A compression spring 87 mounted on transversemember 18 forces the latching arm 79 back to the vertical or load position when the latch control arm 83 is released.

Secured approximately in'the center of and on transverse member 17 of lift carriage 16 is a welded A-frame structure 88 comprising a pair of'side members 89 and 90, upper and lower members 91 and 92 and horizontal supporting members 93, 94 and 95.

Secured to the frame structure 88 and transverse member 17, such as by welding, are guide channel members 98 and 99, G-shaped in cross section forming a track, maintained in proper spaced relation, at their lower ends by horizontal member 101 as shown in FIGS. 1 and 2. Mounted for upward and downward movement within the channel members 98 and 99 are channel upright members 102, 183, 104, and 1515 maintained in proper spaced relation, at their upper ends by means of horizontal channel members 107 and additional horizontal brace members 108' and 109, A plurality of laterally extending pins 110 are fixed on the outer surfaces of channel members182 and 105 and project .into' the inner channel members 98 and 99. Rotatably mounted on the outer ends of pin members 116 are rollers 111 which engage the inner surfaces of channel members 98 and 99 as shown in FIGS. 2 and 3.

Movement of the members 102, 103, 104, and 105 within members 98 and 99 is accomplished by hydraulic cylinders 114 and 115 previously mentioned. These cylinders 114 and 115 are secured at their lower ends to member 100 in any suitable way, plungers 118 and 119 are secured to brackets 120 and 121 respectively which are suitably mounted within member 107.

A hook 124 is pivotally mounted on pin 125 extending laterally between upright members 103 and 194. A stop bar 126 is positioned and suitably secured between upright members 103 and 104 preventing hook 124 from swinging inwardly as shown in FIG. 4.

.A pair of safety latch arms 128 and 129 are rigidly connected together, as shown in FIG. 3, by a shaft 139 having extended portions 131 and 132 pivotally mounted within channel members 103 and 164. The arms 128 and 129 having end portions 133 and 134' extending through slots 135 and 136 of channel members 103 and 194 for engaging the bail 139 of bottom dump box 149. A push rod 143 is positioned under one of the latch arms 129 as indicated in FIG. 4, and extends from a stop plate 146, which is suitably secured to the existing frame of the truck, through an opening in channel member 100. The rod 143 is maintained in the proper position by tubular guides 144 and 145.

The operation will be understood by the foregoing description. Briefly summarized, when using a skip box for the conveying and dumping of material, bearing sockets 39 of load attachment 27 and 28 are used to engage the lugs 147 of skip box 148 as indicated in FIG. 6. The releasing latch 79 is used for automatically dumping the contents. When using the bottom dump type box as shown in FIG. 5, the lugs 141 located on the bottom portion 142 pivot on surfaces 29 ofload attachments 27 and 28. Hook 124 of the lift carriage 16 engages bail 139 of the bottom dump box 140. I

Now for a more detailed description of the operation of the present invention, after the truck has been manipulated to position the load attachments 27 and 28 of forks 21 and 22 beneath the lugs 141 and hook 124 has engaged bail 139 of the bottom dump box 149, the operator raises the lift carriage 16 far enough to lift the latter away from the ground and then the truck is operated V to transport the box 14% to its dump destination.

The safety latch arms 128 and 129 automatically latch over the bail 139 as the lift carriage it; is raised preventing the bail 139 from being accidentally disengaged from the hook 124 while in the up position. This is accomplished because as the push rod 143 is raised along with the lift carriage 16, the stop plate 146 remains stationary causing the push rod 143 to drop downward permittin the latch arms 128 and 129 to pivot forward engaging the bail 139. The tubular guides 144 and 145 support the push rod 143 until the lift carriage 16 is lowered sutliciently to engage the stop plate 146 again. As the carriage 16 continues to be lowered, the push rod 143 resting on the stop plate 146 is forced upward, thus causing the latching arms 128 and 129 upward allowing the bail 139 free to be lifted from hook 124.

This same operation can be used for moving larger bottom dump boxes by adjusting the width of the forks 21 and 22. The operator adjusts the width of the forks by manipulating the hydraulic assemblies 31 and 32. Each assembly has a plunger 41 and 42 respectively which pushes against the inside surfaces 48 and 49 of forks 21 and 22 respectively causing the forks to swing outwardly.

When it is desired to dump the contents of the bottom dump box, the truck 14) is positioned so that the box 14%] is above the desired location. The carriage 16 which supports the box is then raised as a unit to the desired elevation such as above a truck bed or gravel pile or the like.

After the box 149 has been elevated to the desired height, the operator actuates the hydraulic cylinders 114 and 115 which causes hook 124 to raise, lifting the main portion of bottom dump box 144) while the carriage 16 together with the lower portion 142 of box 140 remains stationary. During upward movement of the hook 124, the bottom portion 1-2 2 of box 140 begins to pivot forward on lugs 141 as the hinge at point 149', as shown in FIG. 5, continues to rise along with the box. By the time the hook 124 raises the body of the box 140 to the full dump position, as indicated by-140", 141", the contents of the box has been emptied and the operator can ready the box for the next load by moving the truck clear of the dumping area and lowering the hook 124 supporting the box 149 while the contm'ner bottom 142 is still in the tilted or dump position. This causes the container bottom 142 to touch the ground 138 on its edge opposite the hinged side. The lower portion is oriented back to horizontal position by continuing to lower the hook 124- towards its most downward position .so the ground pushes the forward end up, thus effecting a rotation action on lugs 141. When the bottom of the container bottom 142 reaches a position parallel to and resting on the ground, the operator lowers hook 124 supporting the box 140 so as to efiect the closing thereof.

When using a skip box, the operator manipulates the truck 11) so as to engage the lugs 147 of skip box 148 with the bearing sockets 30 of the load attachments 21 and 22. While positioning the skip box for pick up, the operator momentarily releases the latching arm 7 9 by pulling line 85 attached to the latch control arm 83, allowing the latching arm 79 to pivot rearwardly permitting the box to be firmly seated within the lift forks 21 and 22. Upon releasing the control arm 83, the latching arm 79 pivots forward maintaining the skip box 148 to the hold position. When it is desired to discharge the material, the operator positions the skip box above the desired location and pulls line 85 releasing the latch arm 79 permitting the box to pivot forward on lugs 147; the container automatically tilts forward enough to empty the contents. Repositioning the box to the load position is done in the same manner as the bottom dump box 140. As the skip Obviously many modifications and variations of the v present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. An apparatus, for use with an industrial lift truck in picking up, transporting and dumping both bottom-dump and skip-box types of containers both of which have outwardly-projecting lateral lugs, comprising a frame, a fork-supporting carriage slideably mounted on said frame for selective vertical movement therealong, means connected to said carriage for controlling the vertical position of said carriage along said frame, load supporting elevator means slideably mounted on said carriage for selective vertical movement therealong, means connected to said elevator means for controlling the vertical position of said elevator means along said carriage, a first controllably engageable and releaseable latching means attached to said elevator means and adapted to engage complementary means on the upper portion of a bottom-dump type container for enabling hoisting of the upper portion of said bottom-dump type container by said elevator means for dumping purposes, a second controllably engageable and releasable latching means mounted on said carriage for maintaining a skip-box type container in horizontal, upright position until released to allow dumping of said container, a pair of laterally-spaced L-shaped load supporting forks pivotally mounted on said carriage, means connected to said forks for controllably pivoting said forks, in unison, toward or away from one another to establish a selected lateral spacing between the lower substantially horizontally-extending portions of said respective forks, and a pair of load supporting attachment means each of which is carried respectively by the lower substantially horizontally-extending portion of each of said forks for enabling said forks to accommodatingly support by means of the laterally-extending lugs of the containers a range of different sized containers of both the bottom-dump and skip-box types, each of said lead supporting attachment means running substantially the length of the horizontally-extending fork portion by which it is carried and each of said load supporting attachment means being formed in part by a sloped planar surface member extending upwardly from the inboard edge of said horizontal fork portion, said sloped planar surface member being inclined at an angle in a direction toward the outboard edge of said horizontal fork portion and defining at its upper most limit a horizontally-extending bearing surface which is adapted to support the lugs of bottom-dump type containers, saidplanar surface member being formed at its lower section which is farthest removed from the vertical portion of said L-shaped fork 'with a freely accessible socket adapted to engage lugs of skip-box type containers, and in part by a supporting member also extending upwardly from said horizontal fork portion to supportingly mate with said sloped planar surface member at a location below said bearing surface for the purpose of buttressing said sloped planar surface member.

2. The apparatus of claim 1 wherein said planar surface member and said supporting member form substantially equal angles with said horizontal fork portion.

3. The apparatus of claim 1 wherein said horizontallyextending bearing surface is formed with an upwardly curved hooked portion at its end farthest removed from the vertically extending portion of said fork so as to prevent accidental disengagement of said bearing surface thereby.

' 4. An apparatus, for use with an industrial lift truck in picking up, transporting and dumping both bottomdump and skip-box types of containers both of which have outWardlyeprojectin'g lateral lugs, comprising'a frame, a

fork-supporting carriage slideably mounted on said frame forselective vertical movement therealong', means connected to said carriage for controlling the vertical position of said carriage along said frame, load supporting elevator means slideably mounted on said carriage for selective vertical movement therealong, means connected to said elevator means for controlling the vertical position of said elevator means along said carriage, a first controllably engageable and releasable latching means attached to said elevator means and adapted to engage complementary means on the upper portion of a bottom-dump type container for enabling hoisting of the upper portion of said bottom-dump type container by said elevator means for dumping purposes, a'second controllably engageable and releasable latching means mounted on said carriage for maintaining a skip-box type container in horizontal, upright position until released to allow dumping of said container, 2. pair of laterally-spaced L-shaped load supporting forks pivotally mounted on said carriage, means connected to said forks for controllably pivoting said forks, in unison, toward or away from one another to establish a selected lateral spacing between the lower substantially horizontally-extending portions of said respective forks, and a pair of load supporting attachment means each of which is carried respectively by the lower substantially horizontally-extending portion of each of said forks for enabling said forks to accommodatingly support by means of the laterally-extending lugs of the containers a range of different sized containers of both the bottom-dump and skip-box types, each of said load supporting attachment means extending along a substantial part of the length of the horizontally-extending fork portion by which it is carriedtand consisting of a sloped planar surface member extending upwardly from substantially the inboard edge of said horizontal fork portion, said sloped planar surface member being inclined at an angle in a direction toward the outboard edge of said horizontal fork portion and defining at its upper limit a horizontally-extending bearing surface which is adapted to support the lugs of bottom-dump containers, said planar surface member being formed at its lower section which is farthest removed from the vertical portion of said L- shaped fork with a freely accessible socket adapted to engage lugs of skip box type containers.

5. The apparatus of claim 4 wherein said horizontallyextending bearing surface is formed with an upwardly curved hooked portion at its end farthest removed from the vertically extending portion of said fork so as to prevent accidental disengagement of said bearing surface from the lug of a bottom-dump type container supported thereby.

References Cited in the file of this patent UNITED STATES PATENTS 2,599,023 Vogelet al; May 23, 1950 2,678,743 Backofen et al May 18, 1954 2,713,431 Koehler luly 19, 1955 2,788,143 Parcell Apr. 9, 1957 2,921,703 Dempster et al Ian. 19, 1969 2,923,424 Herpich et al Feb. 2, 1960 FOREIGN PATENTS 317,334 Switzerland Dec. 29, 195% 

